There is no doubt that time spent on warming up and cooling down will improve a person’s level of performance and speed up the recovery process needed before and after training. Warm ups should include aspects which are going to gradually increase cardiovascular activity to increase the heart rate for example, brisk walking, gentle jogging etc.
The other aspects are the stretches to improve mobility. There has been much discussion as to static versus dynamic stretching, and it is generally felt that dynamic stretches are better in a warm up. They help pre-stretch and activate the muscles without overstretching them, as static stretching tends to do. Therefore-they are an effective and safe way to warm up the muscles prior to exercise, and are sports-specific movement it prepares the body for the activity to come.
Contrary to static stretching dynamic stretching does not concentrate on stretching one single muscle, but rather to simulate movements that are important for a certain activity or sports. An example of dynamic stretching is lifting one knee as high as possible while walking as preparation of a 100m sprint. Such dynamic exercises involve active full range of motion movements and quick stretches slightly greater than normal range of motion. Other examples could be lunges, arm circles, butt-kickers, trying to kick your own bottom.
However, the other aspects of a warm up is the need to ‘warm up’ the nervous system not just to enable nerves to work with individual muscles, but it is important to have good postural control. This is the body’s ability to act automatically to control its equilibrium in response to feedback from the eyes, ears, muscles tendons ligaments etc., including aspects such as balance and spatial awareness. Having this postural control ensures that the body’s ability to prepare for movement in response to an impulse to move, a response that triggers weight shifting and stabilizing activity to produce the foundation for movement . For example, variations of squats and lunges for runners to enable integration between legs, pelvis, trunk and upper extremities.
So, to recap, the warm up is important for a range of reasons, to gear up the cardiovascular system, to improve mobility and to activate our nervous muscular system to produce safe coordinated movement patterning.
Here is a video of warm up which I think is a good basic one.